[babl] build: gir - set nsversion from api_version var

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 5aaa30190d8d7718eec2625422920e9612ca808f
Author: John Marshall <jtm home gmail com>
Date:   Wed Jun 24 20:14:34 2020 +0100

    build: gir - set nsversion from api_version var

 babl/meson.build | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/babl/meson.build b/babl/meson.build
index c72fd80ee..146790128 100644
--- a/babl/meson.build
+++ b/babl/meson.build
@@ -155,16 +155,15 @@ babl = library(
 if build_gir
   # identity filter, so GIR doesn't choke on the Babl type
   # (since it has the same name as the Babl namespace)
-  identfilter_py = join_paths(meson.current_source_dir(), 'identfilter.py')
-
   babl_gir = gnome.generate_gir(babl,
     sources: babl_headers,
     extra_args: [
-      '--identifier-filter-cmd=@0@ @1@'.format(python.path(), identfilter_py),
+      '--identifier-filter-cmd=@0@ @1@'.format(python.path(), 
+        meson.current_source_dir() / 'identfilter.py'),
       '-DBABL_IS_BEING_COMPILED',
     ],
     namespace: 'Babl',
-    nsversion: '0.1',
+    nsversion: api_version,
     header: 'babl.h',
     install: true,
   )